<!doctype html>

<html>

<head>

    <meta charset="utf-8">

    <title>无标题文档</title>

</head>

<style>
    body {

        padding: 0;

        margin: 0;

        overflow: hidden;

        height: 600px;

    }

    canvas {

        padding: 0;

        margin: 0;

    }

    div.btnbg {

        position: fixed;

        left: 0;

        top: 0;

    }
</style>

<body>

    <canvas id="sakura"></canvas>

    <div class="btnbg"></div>



    <!-- sakura shader -->

    <script id="sakura_point_vsh" type="x-shader/x_vertex">

uniform mat4 uProjection;

uniform mat4 uModelview;

uniform vec3 uResolution;

uniform vec3 uOffset;

uniform vec3 uDOF;  //x:focus distance, y:focus radius, z:max radius

uniform vec3 uFade; //x:start distance, y:half distance, z:near fade start



attribute vec3 aPosition;

attribute vec3 aEuler;

attribute vec2 aMisc; //x:size, y:fade



varying vec3 pposition;

varying float psize;

varying float palpha;

varying float pdist;



//varying mat3 rotMat;

varying vec3 normX;

varying vec3 normY;

varying vec3 normZ;

varying vec3 normal;



varying float diffuse;

varying float specular;

varying float rstop;

varying float distancefade;



void main(void) {

    // Projection is based on vertical angle

    vec4 pos = uModelview * vec4(aPosition + uOffset, 1.0);

    gl_Position = uProjection * pos;

    gl_PointSize = aMisc.x * uProjection[1][1] / -pos.z * uResolution.y * 0.5;

    

    pposition = pos.xyz;

    psize = aMisc.x;

    pdist = length(pos.xyz);

    palpha = smoothstep(0.0, 1.0, (pdist - 0.1) / uFade.z);

    

    vec3 elrsn = sin(aEuler);

    vec3 elrcs = cos(aEuler);

    mat3 rotx = mat3(

        1.0, 0.0, 0.0,

        0.0, elrcs.x, elrsn.x,

        0.0, -elrsn.x, elrcs.x

    );

    mat3 roty = mat3(

        elrcs.y, 0.0, -elrsn.y,

        0.0, 1.0, 0.0,

        elrsn.y, 0.0, elrcs.y

    );

    mat3 rotz = mat3(

        elrcs.z, elrsn.z, 0.0, 

        -elrsn.z, elrcs.z, 0.0,

        0.0, 0.0, 1.0

    );

    mat3 rotmat = rotx * roty * rotz;

    normal = rotmat[2];

    

    mat3 trrotm = mat3(

        rotmat[0][0], rotmat[1][0], rotmat[2][0],

        rotmat[0][1], rotmat[1][1], rotmat[2][1],

        rotmat[0][2], rotmat[1][2], rotmat[2][2]

    );

    normX = trrotm[0];

    normY = trrotm[1];

    normZ = trrotm[2];

    

    const vec3 lit = vec3(0.6917144638660746, 0.6917144638660746, -0.20751433915982237);

    

    float tmpdfs = dot(lit, normal);

    if(tmpdfs < 0.0) {

        normal = -normal;

        tmpdfs = dot(lit, normal);

    }

    diffuse = 0.4 + tmpdfs;

    

    vec3 eyev = normalize(-pos.xyz);

    if(dot(eyev, normal) > 0.0) {

        vec3 hv = normalize(eyev + lit);

        specular = pow(max(dot(hv, normal), 0.0), 20.0);

    }

    else {

        specular = 0.0;

    }

    

    rstop = clamp((abs(pdist - uDOF.x) - uDOF.y) / uDOF.z, 0.0, 1.0);

    rstop = pow(rstop, 0.5);

    //-0.69315 = ln(0.5)

    distancefade = min(1.0, exp((uFade.x - pdist) * 0.69315 / uFade.y));

}

</script>

    <script id="sakura_point_fsh" type="x-shader/x_fragment">

#ifdef GL_ES

//precision mediump float;

precision highp float;

#endif



uniform vec3 uDOF;  //x:focus distance, y:focus radius, z:max radius

uniform vec3 uFade; //x:start distance, y:half distance, z:near fade start



const vec3 fadeCol = vec3(0.08, 0.03, 0.06);



varying vec3 pposition;

varying float psize;

varying float palpha;

varying float pdist;



//varying mat3 rotMat;

varying vec3 normX;

varying vec3 normY;

varying vec3 normZ;

varying vec3 normal;



varying float diffuse;

varying float specular;

varying float rstop;

varying float distancefade;



float ellipse(vec2 p, vec2 o, vec2 r) {

    vec2 lp = (p - o) / r;

    return length(lp) - 1.0;

}



void main(void) {

    vec3 p = vec3(gl_PointCoord - vec2(0.5, 0.5), 0.0) * 2.0;

    vec3 d = vec3(0.0, 0.0, -1.0);

    float nd = normZ.z; //dot(-normZ, d);

    if(abs(nd) < 0.0001) discard;

    

    float np = dot(normZ, p);

    vec3 tp = p + d * np / nd;

    vec2 coord = vec2(dot(normX, tp), dot(normY, tp));

    

    //angle = 15 degree

    const float flwrsn = 0.258819045102521;

    const float flwrcs = 0.965925826289068;

    mat2 flwrm = mat2(flwrcs, -flwrsn, flwrsn, flwrcs);

    vec2 flwrp = vec2(abs(coord.x), coord.y) * flwrm;

    

    float r;

    if(flwrp.x < 0.0) {

        r = ellipse(flwrp, vec2(0.065, 0.024) * 0.5, vec2(0.36, 0.96) * 0.5);

    }

    else {

        r = ellipse(flwrp, vec2(0.065, 0.024) * 0.5, vec2(0.58, 0.96) * 0.5);

    }

    

    if(r > rstop) discard;

    

    vec3 col = mix(vec3(1.0, 0.8, 0.75), vec3(1.0, 0.9, 0.87), r);

    float grady = mix(0.0, 1.0, pow(coord.y * 0.5 + 0.5, 0.35));

    col *= vec3(1.0, grady, grady);

    col *= mix(0.8, 1.0, pow(abs(coord.x), 0.3));

    col = col * diffuse + specular;

    

    col = mix(fadeCol, col, distancefade);

    

    float alpha = (rstop > 0.001)? (0.5 - r / (rstop * 2.0)) : 1.0;

    alpha = smoothstep(0.0, 1.0, alpha) * palpha;

    

    gl_FragColor = vec4(col * 0.5, alpha);

}

</script>

    <!-- effects -->

    <script id="fx_common_vsh" type="x-shader/x_vertex">

uniform vec3 uResolution;

attribute vec2 aPosition;



varying vec2 texCoord;

varying vec2 screenCoord;



void main(void) {

    gl_Position = vec4(aPosition, 0.0, 1.0);

    texCoord = aPosition.xy * 0.5 + vec2(0.5, 0.5);

    screenCoord = aPosition.xy * vec2(uResolution.z, 1.0);

}

</script>

    <script id="bg_fsh" type="x-shader/x_fragment">

#ifdef GL_ES

//precision mediump float;

precision highp float;

#endif



uniform vec2 uTimes;



varying vec2 texCoord;

varying vec2 screenCoord;



void main(void) {

    vec3 col;

    float c;

    vec2 tmpv = texCoord * vec2(0.8, 1.0) - vec2(0.95, 1.0);

    c = exp(-pow(length(tmpv) * 1.8, 2.0));

    col = mix(vec3(0.02, 0.0, 0.03), vec3(0.96, 0.98, 1.0) * 1.5, c);

    gl_FragColor = vec4(col * 0.5, 1.0);

}

</script>

    <script id="fx_brightbuf_fsh" type="x-shader/x_fragment">

#ifdef GL_ES

//precision mediump float;

precision highp float;

#endif

uniform sampler2D uSrc;

uniform vec2 uDelta;



varying vec2 texCoord;

varying vec2 screenCoord;



void main(void) {

    vec4 col = texture2D(uSrc, texCoord);

    gl_FragColor = vec4(col.rgb * 2.0 - vec3(0.5), 1.0);

}

</script>

    <script id="fx_dirblur_r4_fsh" type="x-shader/x_fragment">

#ifdef GL_ES

//precision mediump float;

precision highp float;

#endif

uniform sampler2D uSrc;

uniform vec2 uDelta;

uniform vec4 uBlurDir; //dir(x, y), stride(z, w)



varying vec2 texCoord;

varying vec2 screenCoord;



void main(void) {

    vec4 col = texture2D(uSrc, texCoord);

    col = col + texture2D(uSrc, texCoord + uBlurDir.xy * uDelta);

    col = col + texture2D(uSrc, texCoord - uBlurDir.xy * uDelta);

    col = col + texture2D(uSrc, texCoord + (uBlurDir.xy + uBlurDir.zw) * uDelta);

    col = col + texture2D(uSrc, texCoord - (uBlurDir.xy + uBlurDir.zw) * uDelta);

    gl_FragColor = col / 5.0;

}

</script>

    <!-- effect fragment shader template -->

    <script id="fx_common_fsh" type="x-shader/x_fragment">

#ifdef GL_ES

//precision mediump float;

precision highp float;

#endif

uniform sampler2D uSrc;

uniform vec2 uDelta;



varying vec2 texCoord;

varying vec2 screenCoord;



void main(void) {

    gl_FragColor = texture2D(uSrc, texCoord);

}

</script>

    <!-- post processing -->

    <script id="pp_final_vsh" type="x-shader/x_vertex">

uniform vec3 uResolution;

attribute vec2 aPosition;

varying vec2 texCoord;

varying vec2 screenCoord;

void main(void) {

    gl_Position = vec4(aPosition, 0.0, 1.0);

    texCoord = aPosition.xy * 0.5 + vec2(0.5, 0.5);

    screenCoord = aPosition.xy * vec2(uResolution.z, 1.0);

}

</script>

    <script id="pp_final_fsh" type="x-shader/x_fragment">

#ifdef GL_ES

//precision mediump float;

precision highp float;

#endif

uniform sampler2D uSrc;

uniform sampler2D uBloom;

uniform vec2 uDelta;

varying vec2 texCoord;

varying vec2 screenCoord;

void main(void) {

    vec4 srccol = texture2D(uSrc, texCoord) * 2.0;

    vec4 bloomcol = texture2D(uBloom, texCoord);

    vec4 col;

    col = srccol + bloomcol * (vec4(1.0) + srccol);

    col *= smoothstep(1.0, 0.0, pow(length((texCoord - vec2(0.5)) * 2.0), 1.2) * 0.5);

    col = pow(col, vec4(0.45454545454545)); //(1.0 / 2.2)

    

    gl_FragColor = vec4(col.rgb, 1.0);

    gl_FragColor.a = 1.0;

}

</script>

</body>

<script>

    // Utilities

    var Vector3 = {};

    var Matrix44 = {};

    Vector3.create = function (x, y, z) {

        return { 'x': x, 'y': y, 'z': z };

    };

    Vector3.dot = function (v0, v1) {

        return v0.x * v1.x + v0.y * v1.y + v0.z * v1.z;

    };

    Vector3.cross = function (v, v0, v1) {

        v.x = v0.y * v1.z - v0.z * v1.y;

        v.y = v0.z * v1.x - v0.x * v1.z;

        v.z = v0.x * v1.y - v0.y * v1.x;

    };

    Vector3.normalize = function (v) {

        var l = v.x * v.x + v.y * v.y + v.z * v.z;

        if (l > 0.00001) {

            l = 1.0 / Math.sqrt(l);

            v.x *= l;

            v.y *= l;

            v.z *= l;

        }

    };

    Vector3.arrayForm = function (v) {

        if (v.array) {

            v.array[0] = v.x;

            v.array[1] = v.y;

            v.array[2] = v.z;

        }

        else {

            v.array = new Float32Array([v.x, v.y, v.z]);

        }

        return v.array;

    };

    Matrix44.createIdentity = function () {

        return new Float32Array([1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0]);

    };

    Matrix44.loadProjection = function (m, aspect, vdeg, near, far) {

        var h = near * Math.tan(vdeg * Math.PI / 180.0 * 0.5) * 2.0;

        var w = h * aspect;



        m[0] = 2.0 * near / w;

        m[1] = 0.0;

        m[2] = 0.0;

        m[3] = 0.0;



        m[4] = 0.0;

        m[5] = 2.0 * near / h;

        m[6] = 0.0;

        m[7] = 0.0;



        m[8] = 0.0;

        m[9] = 0.0;

        m[10] = -(far + near) / (far - near);

        m[11] = -1.0;



        m[12] = 0.0;

        m[13] = 0.0;

        m[14] = -2.0 * far * near / (far - near);

        m[15] = 0.0;

    };

    Matrix44.loadLookAt = function (m, vpos, vlook, vup) {

        var frontv = Vector3.create(vpos.x - vlook.x, vpos.y - vlook.y, vpos.z - vlook.z);

        Vector3.normalize(frontv);

        var sidev = Vector3.create(1.0, 0.0, 0.0);

        Vector3.cross(sidev, vup, frontv);

        Vector3.normalize(sidev);

        var topv = Vector3.create(1.0, 0.0, 0.0);

        Vector3.cross(topv, frontv, sidev);

        Vector3.normalize(topv);



        m[0] = sidev.x;

        m[1] = topv.x;

        m[2] = frontv.x;

        m[3] = 0.0;



        m[4] = sidev.y;

        m[5] = topv.y;

        m[6] = frontv.y;

        m[7] = 0.0;



        m[8] = sidev.z;

        m[9] = topv.z;

        m[10] = frontv.z;

        m[11] = 0.0;



        m[12] = -(vpos.x * m[0] + vpos.y * m[4] + vpos.z * m[8]);

        m[13] = -(vpos.x * m[1] + vpos.y * m[5] + vpos.z * m[9]);

        m[14] = -(vpos.x * m[2] + vpos.y * m[6] + vpos.z * m[10]);

        m[15] = 1.0;

    };



    //

    var timeInfo = {

        'start': 0, 'prev': 0, // Date

        'delta': 0, 'elapsed': 0 // Number(sec)

    };



    //

    var gl;

    var renderSpec = {

        'width': 0,

        'height': 0,

        'aspect': 1,

        'array': new Float32Array(3),

        'halfWidth': 0,

        'halfHeight': 0,

        'halfArray': new Float32Array(3)

        // and some render targets. see setViewport()

    };

    renderSpec.setSize = function (w, h) {

        renderSpec.width = w;

        renderSpec.height = h;

        renderSpec.aspect = renderSpec.width / renderSpec.height;

        renderSpec.array[0] = renderSpec.width;

        renderSpec.array[1] = renderSpec.height;

        renderSpec.array[2] = renderSpec.aspect;



        renderSpec.halfWidth = Math.floor(w / 2);

        renderSpec.halfHeight = Math.floor(h / 2);

        renderSpec.halfArray[0] = renderSpec.halfWidth;

        renderSpec.halfArray[1] = renderSpec.halfHeight;

        renderSpec.halfArray[2] = renderSpec.halfWidth / renderSpec.halfHeight;

    };



    function deleteRenderTarget(rt) {

        gl.deleteFramebuffer(rt.frameBuffer);

        gl.deleteRenderbuffer(rt.renderBuffer);

        gl.deleteTexture(rt.texture);

    }



    function createRenderTarget(w, h) {

        var ret = {

            'width': w,

            'height': h,

            'sizeArray': new Float32Array([w, h, w / h]),

            'dtxArray': new Float32Array([1.0 / w, 1.0 / h])

        };

        ret.frameBuffer = gl.createFramebuffer();

        ret.renderBuffer = gl.createRenderbuffer();

        ret.texture = gl.createTexture();



        gl.bindTexture(gl.TEXTURE_2D, ret.texture);

        gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, w, h, 0, gl.RGBA, gl.UNSIGNED_BYTE, null);

        gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);

        gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);

        gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);

        gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);



        gl.bindFramebuffer(gl.FRAMEBUFFER, ret.frameBuffer);

        gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, ret.texture, 0);



        gl.bindRenderbuffer(gl.RENDERBUFFER, ret.renderBuffer);

        gl.renderbufferStorage(gl.RENDERBUFFER, gl.DEPTH_COMPONENT16, w, h);

        gl.framebufferRenderbuffer(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.RENDERBUFFER, ret.renderBuffer);



        gl.bindTexture(gl.TEXTURE_2D, null);

        gl.bindRenderbuffer(gl.RENDERBUFFER, null);

        gl.bindFramebuffer(gl.FRAMEBUFFER, null);



        return ret;

    }



    function compileShader(shtype, shsrc) {

        var retsh = gl.createShader(shtype);



        gl.shaderSource(retsh, shsrc);

        gl.compileShader(retsh);



        if (!gl.getShaderParameter(retsh, gl.COMPILE_STATUS)) {

            var errlog = gl.getShaderInfoLog(retsh);

            gl.deleteShader(retsh);

            console.error(errlog);

            return null;

        }

        return retsh;

    }



    function createShader(vtxsrc, frgsrc, uniformlist, attrlist) {

        var vsh = compileShader(gl.VERTEX_SHADER, vtxsrc);

        var fsh = compileShader(gl.FRAGMENT_SHADER, frgsrc);



        if (vsh == null || fsh == null) {

            return null;

        }



        var prog = gl.createProgram();

        gl.attachShader(prog, vsh);

        gl.attachShader(prog, fsh);



        gl.deleteShader(vsh);

        gl.deleteShader(fsh);



        gl.linkProgram(prog);

        if (!gl.getProgramParameter(prog, gl.LINK_STATUS)) {

            var errlog = gl.getProgramInfoLog(prog);

            console.error(errlog);

            return null;

        }



        if (uniformlist) {

            prog.uniforms = {};

            for (var i = 0; i < uniformlist.length; i++) {

                prog.uniforms[uniformlist[i]] = gl.getUniformLocation(prog, uniformlist[i]);

            }

        }



        if (attrlist) {

            prog.attributes = {};

            for (var i = 0; i < attrlist.length; i++) {

                var attr = attrlist[i];

                prog.attributes[attr] = gl.getAttribLocation(prog, attr);

            }

        }



        return prog;

    }



    function useShader(prog) {

        gl.useProgram(prog);

        for (var attr in prog.attributes) {

            gl.enableVertexAttribArray(prog.attributes[attr]);;

        }

    }



    function unuseShader(prog) {

        for (var attr in prog.attributes) {

            gl.disableVertexAttribArray(prog.attributes[attr]);;

        }

        gl.useProgram(null);

    }



    /////

    var projection = {

        'angle': 60,

        'nearfar': new Float32Array([0.1, 100.0]),

        'matrix': Matrix44.createIdentity()

    };

    var camera = {

        'position': Vector3.create(0, 0, 100),

        'lookat': Vector3.create(0, 0, 0),

        'up': Vector3.create(0, 1, 0),

        'dof': Vector3.create(10.0, 4.0, 8.0),

        'matrix': Matrix44.createIdentity()

    };



    var pointFlower = {};

    var meshFlower = {};

    var sceneStandBy = false;



    var BlossomParticle = function () {

        this.velocity = new Array(3);

        this.rotation = new Array(3);

        this.position = new Array(3);

        this.euler = new Array(3);

        this.size = 1.0;

        this.alpha = 1.0;

        this.zkey = 0.0;

    };



    BlossomParticle.prototype.setVelocity = function (vx, vy, vz) {

        this.velocity[0] = vx;

        this.velocity[1] = vy;

        this.velocity[2] = vz;

    };



    BlossomParticle.prototype.setRotation = function (rx, ry, rz) {

        this.rotation[0] = rx;

        this.rotation[1] = ry;

        this.rotation[2] = rz;

    };



    BlossomParticle.prototype.setPosition = function (nx, ny, nz) {

        this.position[0] = nx;

        this.position[1] = ny;

        this.position[2] = nz;

    };



    BlossomParticle.prototype.setEulerAngles = function (rx, ry, rz) {

        this.euler[0] = rx;

        this.euler[1] = ry;

        this.euler[2] = rz;

    };



    BlossomParticle.prototype.setSize = function (s) {

        this.size = s;

    };



    BlossomParticle.prototype.update = function (dt, et) {

        this.position[0] += this.velocity[0] * dt;

        this.position[1] += this.velocity[1] * dt;

        this.position[2] += this.velocity[2] * dt;



        this.euler[0] += this.rotation[0] * dt;

        this.euler[1] += this.rotation[1] * dt;

        this.euler[2] += this.rotation[2] * dt;

    };



    function createPointFlowers() {

        // get point sizes

        var prm = gl.getParameter(gl.ALIASED_POINT_SIZE_RANGE);

        renderSpec.pointSize = { 'min': prm[0], 'max': prm[1] };



        var vtxsrc = document.getElementById("sakura_point_vsh").textContent;

        var frgsrc = document.getElementById("sakura_point_fsh").textContent;



        pointFlower.program = createShader(

            vtxsrc, frgsrc,

            ['uProjection', 'uModelview', 'uResolution', 'uOffset', 'uDOF', 'uFade'],

            ['aPosition', 'aEuler', 'aMisc']

        );



        useShader(pointFlower.program);

        pointFlower.offset = new Float32Array([0.0, 0.0, 0.0]);

        pointFlower.fader = Vector3.create(0.0, 10.0, 0.0);



        // paramerters: velocity[3], rotate[3]

        pointFlower.numFlowers = 1600;

        pointFlower.particles = new Array(pointFlower.numFlowers);

        // vertex attributes {position[3], euler_xyz[3], size[1]}

        pointFlower.dataArray = new Float32Array(pointFlower.numFlowers * (3 + 3 + 2));

        pointFlower.positionArrayOffset = 0;

        pointFlower.eulerArrayOffset = pointFlower.numFlowers * 3;

        pointFlower.miscArrayOffset = pointFlower.numFlowers * 6;



        pointFlower.buffer = gl.createBuffer();

        gl.bindBuffer(gl.ARRAY_BUFFER, pointFlower.buffer);

        gl.bufferData(gl.ARRAY_BUFFER, pointFlower.dataArray, gl.DYNAMIC_DRAW);

        gl.bindBuffer(gl.ARRAY_BUFFER, null);



        unuseShader(pointFlower.program);



        for (var i = 0; i < pointFlower.numFlowers; i++) {

            pointFlower.particles[i] = new BlossomParticle();

        }

    }



    function initPointFlowers() {

        //area

        pointFlower.area = Vector3.create(20.0, 20.0, 20.0);

        pointFlower.area.x = pointFlower.area.y * renderSpec.aspect;



        pointFlower.fader.x = 10.0; //env fade start

        pointFlower.fader.y = pointFlower.area.z; //env fade half

        pointFlower.fader.z = 0.1;  //near fade start



        //particles

        var PI2 = Math.PI * 2.0;

        var tmpv3 = Vector3.create(0, 0, 0);

        var tmpv = 0;

        var symmetryrand = function () { return (Math.random() * 2.0 - 1.0); };

        for (var i = 0; i < pointFlower.numFlowers; i++) {

            var tmpprtcl = pointFlower.particles[i];



            //velocity

            tmpv3.x = symmetryrand() * 0.3 + 0.8;

            tmpv3.y = symmetryrand() * 0.2 - 1.0;

            tmpv3.z = symmetryrand() * 0.3 + 0.5;

            Vector3.normalize(tmpv3);

            tmpv = 2.0 + Math.random() * 1.0;

            tmpprtcl.setVelocity(tmpv3.x * tmpv, tmpv3.y * tmpv, tmpv3.z * tmpv);



            //rotation

            tmpprtcl.setRotation(

                symmetryrand() * PI2 * 0.5,

                symmetryrand() * PI2 * 0.5,

                symmetryrand() * PI2 * 0.5

            );



            //position

            tmpprtcl.setPosition(

                symmetryrand() * pointFlower.area.x,

                symmetryrand() * pointFlower.area.y,

                symmetryrand() * pointFlower.area.z

            );



            //euler

            tmpprtcl.setEulerAngles(

                Math.random() * Math.PI * 2.0,

                Math.random() * Math.PI * 2.0,

                Math.random() * Math.PI * 2.0

            );



            //size

            tmpprtcl.setSize(0.9 + Math.random() * 0.1);

        }

    }



    function renderPointFlowers() {

        //update

        var PI2 = Math.PI * 2.0;

        var limit = [pointFlower.area.x, pointFlower.area.y, pointFlower.area.z];

        var repeatPos = function (prt, cmp, limit) {

            if (Math.abs(prt.position[cmp]) - prt.size * 0.5 > limit) {

                //out of area

                if (prt.position[cmp] > 0) {

                    prt.position[cmp] -= limit * 2.0;

                }

                else {

                    prt.position[cmp] += limit * 2.0;

                }

            }

        };

        var repeatEuler = function (prt, cmp) {

            prt.euler[cmp] = prt.euler[cmp] % PI2;

            if (prt.euler[cmp] < 0.0) {

                prt.euler[cmp] += PI2;

            }

        };



        for (var i = 0; i < pointFlower.numFlowers; i++) {

            var prtcl = pointFlower.particles[i];

            prtcl.update(timeInfo.delta, timeInfo.elapsed);

            repeatPos(prtcl, 0, pointFlower.area.x);

            repeatPos(prtcl, 1, pointFlower.area.y);

            repeatPos(prtcl, 2, pointFlower.area.z);

            repeatEuler(prtcl, 0);

            repeatEuler(prtcl, 1);

            repeatEuler(prtcl, 2);



            prtcl.alpha = 1.0;//(pointFlower.area.z - prtcl.position[2]) * 0.5;



            prtcl.zkey = (camera.matrix[2] * prtcl.position[0]

                + camera.matrix[6] * prtcl.position[1]

                + camera.matrix[10] * prtcl.position[2]

                + camera.matrix[14]);

        }



        // sort

        pointFlower.particles.sort(function (p0, p1) { return p0.zkey - p1.zkey; });



        // update data

        var ipos = pointFlower.positionArrayOffset;

        var ieuler = pointFlower.eulerArrayOffset;

        var imisc = pointFlower.miscArrayOffset;

        for (var i = 0; i < pointFlower.numFlowers; i++) {

            var prtcl = pointFlower.particles[i];

            pointFlower.dataArray[ipos] = prtcl.position[0];

            pointFlower.dataArray[ipos + 1] = prtcl.position[1];

            pointFlower.dataArray[ipos + 2] = prtcl.position[2];

            ipos += 3;

            pointFlower.dataArray[ieuler] = prtcl.euler[0];

            pointFlower.dataArray[ieuler + 1] = prtcl.euler[1];

            pointFlower.dataArray[ieuler + 2] = prtcl.euler[2];

            ieuler += 3;

            pointFlower.dataArray[imisc] = prtcl.size;

            pointFlower.dataArray[imisc + 1] = prtcl.alpha;

            imisc += 2;

        }



        //draw

        gl.enable(gl.BLEND);

        //gl.disable(gl.DEPTH_TEST);

        gl.blendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA);



        var prog = pointFlower.program;

        useShader(prog);



        gl.uniformMatrix4fv(prog.uniforms.uProjection, false, projection.matrix);

        gl.uniformMatrix4fv(prog.uniforms.uModelview, false, camera.matrix);

        gl.uniform3fv(prog.uniforms.uResolution, renderSpec.array);

        gl.uniform3fv(prog.uniforms.uDOF, Vector3.arrayForm(camera.dof));

        gl.uniform3fv(prog.uniforms.uFade, Vector3.arrayForm(pointFlower.fader));



        gl.bindBuffer(gl.ARRAY_BUFFER, pointFlower.buffer);

        gl.bufferData(gl.ARRAY_BUFFER, pointFlower.dataArray, gl.DYNAMIC_DRAW);



        gl.vertexAttribPointer(prog.attributes.aPosition, 3, gl.FLOAT, false, 0, pointFlower.positionArrayOffset * Float32Array.BYTES_PER_ELEMENT);

        gl.vertexAttribPointer(prog.attributes.aEuler, 3, gl.FLOAT, false, 0, pointFlower.eulerArrayOffset * Float32Array.BYTES_PER_ELEMENT);

        gl.vertexAttribPointer(prog.attributes.aMisc, 2, gl.FLOAT, false, 0, pointFlower.miscArrayOffset * Float32Array.BYTES_PER_ELEMENT);



        // doubler

        for (var i = 1; i < 2; i++) {

            var zpos = i * -2.0;

            pointFlower.offset[0] = pointFlower.area.x * -1.0;

            pointFlower.offset[1] = pointFlower.area.y * -1.0;

            pointFlower.offset[2] = pointFlower.area.z * zpos;

            gl.uniform3fv(prog.uniforms.uOffset, pointFlower.offset);

            gl.drawArrays(gl.POINT, 0, pointFlower.numFlowers);



            pointFlower.offset[0] = pointFlower.area.x * -1.0;

            pointFlower.offset[1] = pointFlower.area.y * 1.0;

            pointFlower.offset[2] = pointFlower.area.z * zpos;

            gl.uniform3fv(prog.uniforms.uOffset, pointFlower.offset);

            gl.drawArrays(gl.POINT, 0, pointFlower.numFlowers);



            pointFlower.offset[0] = pointFlower.area.x * 1.0;

            pointFlower.offset[1] = pointFlower.area.y * -1.0;

            pointFlower.offset[2] = pointFlower.area.z * zpos;

            gl.uniform3fv(prog.uniforms.uOffset, pointFlower.offset);

            gl.drawArrays(gl.POINT, 0, pointFlower.numFlowers);



            pointFlower.offset[0] = pointFlower.area.x * 1.0;

            pointFlower.offset[1] = pointFlower.area.y * 1.0;

            pointFlower.offset[2] = pointFlower.area.z * zpos;

            gl.uniform3fv(prog.uniforms.uOffset, pointFlower.offset);

            gl.drawArrays(gl.POINT, 0, pointFlower.numFlowers);

        }



        //main

        pointFlower.offset[0] = 0.0;

        pointFlower.offset[1] = 0.0;

        pointFlower.offset[2] = 0.0;

        gl.uniform3fv(prog.uniforms.uOffset, pointFlower.offset);

        gl.drawArrays(gl.POINT, 0, pointFlower.numFlowers);



        gl.bindBuffer(gl.ARRAY_BUFFER, null);

        unuseShader(prog);



        gl.enable(gl.DEPTH_TEST);

        gl.disable(gl.BLEND);

    }



    // effects

    //common util

    function createEffectProgram(vtxsrc, frgsrc, exunifs, exattrs) {

        var ret = {};

        var unifs = ['uResolution', 'uSrc', 'uDelta'];

        if (exunifs) {

            unifs = unifs.concat(exunifs);

        }

        var attrs = ['aPosition'];

        if (exattrs) {

            attrs = attrs.concat(exattrs);

        }



        ret.program = createShader(vtxsrc, frgsrc, unifs, attrs);

        useShader(ret.program);



        ret.dataArray = new Float32Array([

            -1.0, -1.0,

            1.0, -1.0,

            -1.0, 1.0,

            1.0, 1.0

        ]);

        ret.buffer = gl.createBuffer();

        gl.bindBuffer(gl.ARRAY_BUFFER, ret.buffer);

        gl.bufferData(gl.ARRAY_BUFFER, ret.dataArray, gl.STATIC_DRAW);



        gl.bindBuffer(gl.ARRAY_BUFFER, null);

        unuseShader(ret.program);



        return ret;

    }



    // basic usage

    // useEffect(prog, srctex({'texture':texid, 'dtxArray':(f32)[dtx, dty]})); //basic initialize

    // gl.uniform**(...); //additional uniforms

    // drawEffect()

    // unuseEffect(prog)

    // TEXTURE0 makes src

    function useEffect(fxobj, srctex) {

        var prog = fxobj.program;

        useShader(prog);

        gl.uniform3fv(prog.uniforms.uResolution, renderSpec.array);



        if (srctex != null) {

            gl.uniform2fv(prog.uniforms.uDelta, srctex.dtxArray);

            gl.uniform1i(prog.uniforms.uSrc, 0);



            gl.activeTexture(gl.TEXTURE0);

            gl.bindTexture(gl.TEXTURE_2D, srctex.texture);

        }

    }

    function drawEffect(fxobj) {

        gl.bindBuffer(gl.ARRAY_BUFFER, fxobj.buffer);

        gl.vertexAttribPointer(fxobj.program.attributes.aPosition, 2, gl.FLOAT, false, 0, 0);

        gl.drawArrays(gl.TRIANGLE_STRIP, 0, 4);

    }

    function unuseEffect(fxobj) {

        unuseShader(fxobj.program);

    }



    var effectLib = {};

    function createEffectLib() {



        var vtxsrc, frgsrc;

        //common

        var cmnvtxsrc = document.getElementById("fx_common_vsh").textContent;



        //background

        frgsrc = document.getElementById("bg_fsh").textContent;

        effectLib.sceneBg = createEffectProgram(cmnvtxsrc, frgsrc, ['uTimes'], null);



        // make brightpixels buffer

        frgsrc = document.getElementById("fx_brightbuf_fsh").textContent;

        effectLib.mkBrightBuf = createEffectProgram(cmnvtxsrc, frgsrc, null, null);



        // direction blur

        frgsrc = document.getElementById("fx_dirblur_r4_fsh").textContent;

        effectLib.dirBlur = createEffectProgram(cmnvtxsrc, frgsrc, ['uBlurDir'], null);



        //final composite

        vtxsrc = document.getElementById("pp_final_vsh").textContent;

        frgsrc = document.getElementById("pp_final_fsh").textContent;

        effectLib.finalComp = createEffectProgram(vtxsrc, frgsrc, ['uBloom'], null);

    }



    // background

    function createBackground() {

        //console.log("create background");

    }

    function initBackground() {

        //console.log("init background");

    }

    function renderBackground() {

        gl.disable(gl.DEPTH_TEST);



        useEffect(effectLib.sceneBg, null);

        gl.uniform2f(effectLib.sceneBg.program.uniforms.uTimes, timeInfo.elapsed, timeInfo.delta);

        drawEffect(effectLib.sceneBg);

        unuseEffect(effectLib.sceneBg);



        gl.enable(gl.DEPTH_TEST);

    }



    // post process

    var postProcess = {};

    function createPostProcess() {

        //console.log("create post process");

    }

    function initPostProcess() {

        //console.log("init post process");

    }



    function renderPostProcess() {

        gl.enable(gl.TEXTURE_2D);

        gl.disable(gl.DEPTH_TEST);

        var bindRT = function (rt, isclear) {

            gl.bindFramebuffer(gl.FRAMEBUFFER, rt.frameBuffer);

            gl.viewport(0, 0, rt.width, rt.height);

            if (isclear) {

                gl.clearColor(0, 0, 0, 0);

                gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);

            }

        };



        //make bright buff

        bindRT(renderSpec.wHalfRT0, true);

        useEffect(effectLib.mkBrightBuf, renderSpec.mainRT);

        drawEffect(effectLib.mkBrightBuf);

        unuseEffect(effectLib.mkBrightBuf);



        // make bloom

        for (var i = 0; i < 2; i++) {

            var p = 1.5 + 1 * i;

            var s = 2.0 + 1 * i;

            bindRT(renderSpec.wHalfRT1, true);

            useEffect(effectLib.dirBlur, renderSpec.wHalfRT0);

            gl.uniform4f(effectLib.dirBlur.program.uniforms.uBlurDir, p, 0.0, s, 0.0);

            drawEffect(effectLib.dirBlur);

            unuseEffect(effectLib.dirBlur);



            bindRT(renderSpec.wHalfRT0, true);

            useEffect(effectLib.dirBlur, renderSpec.wHalfRT1);

            gl.uniform4f(effectLib.dirBlur.program.uniforms.uBlurDir, 0.0, p, 0.0, s);

            drawEffect(effectLib.dirBlur);

            unuseEffect(effectLib.dirBlur);

        }



        //display

        gl.bindFramebuffer(gl.FRAMEBUFFER, null);

        gl.viewport(0, 0, renderSpec.width, renderSpec.height);

        gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);



        useEffect(effectLib.finalComp, renderSpec.mainRT);

        gl.uniform1i(effectLib.finalComp.program.uniforms.uBloom, 1);

        gl.activeTexture(gl.TEXTURE1);

        gl.bindTexture(gl.TEXTURE_2D, renderSpec.wHalfRT0.texture);

        drawEffect(effectLib.finalComp);

        unuseEffect(effectLib.finalComp);



        gl.enable(gl.DEPTH_TEST);

    }



    /////

    var SceneEnv = {};

    function createScene() {

        createEffectLib();

        createBackground();

        createPointFlowers();

        createPostProcess();

        sceneStandBy = true;

    }



    function initScene() {

        initBackground();

        initPointFlowers();

        initPostProcess();



        //camera.position.z = 17.320508;

        camera.position.z = pointFlower.area.z + projection.nearfar[0];

        projection.angle = Math.atan2(pointFlower.area.y, camera.position.z + pointFlower.area.z) * 180.0 / Math.PI * 2.0;

        Matrix44.loadProjection(projection.matrix, renderSpec.aspect, projection.angle, projection.nearfar[0], projection.nearfar[1]);

    }



    function renderScene() {

        //draw

        Matrix44.loadLookAt(camera.matrix, camera.position, camera.lookat, camera.up);



        gl.enable(gl.DEPTH_TEST);



        //gl.bindFramebuffer(gl.FRAMEBUFFER, null);

        gl.bindFramebuffer(gl.FRAMEBUFFER, renderSpec.mainRT.frameBuffer);

        gl.viewport(0, 0, renderSpec.mainRT.width, renderSpec.mainRT.height);

        gl.clearColor(0.005, 0, 0.05, 0);

        gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);



        renderBackground();

        renderPointFlowers();

        renderPostProcess();

    }



    /////

    function onResize(e) {

        makeCanvasFullScreen(document.getElementById("sakura"));

        setViewports();

        if (sceneStandBy) {

            initScene();

        }

    }



    function setViewports() {

        renderSpec.setSize(gl.canvas.width, gl.canvas.height);



        gl.clearColor(0.2, 0.2, 0.5, 1.0);

        gl.viewport(0, 0, renderSpec.width, renderSpec.height);



        var rtfunc = function (rtname, rtw, rth) {

            var rt = renderSpec[rtname];

            if (rt) deleteRenderTarget(rt);

            renderSpec[rtname] = createRenderTarget(rtw, rth);

        };

        rtfunc('mainRT', renderSpec.width, renderSpec.height);

        rtfunc('wFullRT0', renderSpec.width, renderSpec.height);

        rtfunc('wFullRT1', renderSpec.width, renderSpec.height);

        rtfunc('wHalfRT0', renderSpec.halfWidth, renderSpec.halfHeight);

        rtfunc('wHalfRT1', renderSpec.halfWidth, renderSpec.halfHeight);

    }



    function render() {

        renderScene();

    }



    var animating = true;

    function toggleAnimation(elm) {

        animating ^= true;

        if (animating) animate();

        if (elm) {

            elm.innerHTML = animating ? "Stop" : "Start";

        }

    }



    function stepAnimation() {

        if (!animating) animate();

    }



    function animate() {

        var curdate = new Date();

        timeInfo.elapsed = (curdate - timeInfo.start) / 1000.0;

        timeInfo.delta = (curdate - timeInfo.prev) / 1000.0;

        timeInfo.prev = curdate;



        if (animating) requestAnimationFrame(animate);

        render();

    }



    function makeCanvasFullScreen(canvas) {

        var b = document.body;

        var d = document.documentElement;

        fullw = Math.max(b.clientWidth, b.scrollWidth, d.scrollWidth, d.clientWidth);

        fullh = Math.max(b.clientHeight, b.scrollHeight, d.scrollHeight, d.clientHeight);

        canvas.width = fullw;

        canvas.height = fullh;

    }



    window.addEventListener('load', function (e) {

        var canvas = document.getElementById("sakura");

        try {

            makeCanvasFullScreen(canvas);

            gl = canvas.getContext('experimental-webgl');

        } catch (e) {

            alert("WebGL not supported." + e);

            console.error(e);

            return;

        }



        window.addEventListener('resize', onResize);



        setViewports();

        createScene();

        initScene();



        timeInfo.start = new Date();

        timeInfo.prev = timeInfo.start;

        animate();

    });



    //set window.requestAnimationFrame

    (function (w, r) {

        w['r' + r] = w['r' + r] || w['webkitR' + r] || w['mozR' + r] || w['msR' + r] || w['oR' + r] || function (c) { w.setTimeout(c, 1000 / 60); };

    })(window, 'equestAnimationFrame');

</script>

</html>